Substrate processing apparatuses that perform various types of processing on substrates have conventionally been used in the process of manufacturing semiconductor substrates (hereinafter, simply referred to as “substrates”). For example, Japanese Patent Application Laid-Open No. 2010-93230 (Document 1) discloses a batch-type substrate processing apparatus that processes a plurality of substrates by one operation. In this substrate processing apparatus, a plurality of substrates aligned along the thickness (hereinafter, referred to as a “thickness direction”) of the substrates in a horizontal posture are held and transported by a batch hand. This substrate processing apparatus includes a substrate-direction alignment mechanism for aligning the directions of a plurality of substrates that are held in a vertical posture by a chuck. The substrate-direction alignment mechanism aligns a plurality of substrates at once so that the orientations (i.e., circumferential positions) of notches provided in peripheral portions of the substrates match one another.
A substrate processing apparatus disclosed in Japanese Patent Application Laid-Open No. 2013-258312 (Document 2) includes a notch alignment device that aligns the positions of notches by individually picking up substrates one at a time. This substrate processing apparatus determines the destination to which the substrates are transported by a robot, on the basis of information such as notch alignment progress information that indicates whether notch alignment is completed, and processing progress information that indicates whether processing to be performed on substrates is completed.
Meanwhile, a substrate inspection device disclosed in Japanese Patent Application Laid-Open No. 2006-339574 (Document 3) includes a transport arm that transports a wafer while adsorbing the lower surface of the wafer under vacuum. If the wafer is warped, in order to prevent misdetection of imperfect wafer adsorption by the transport arm, the substrate inspection apparatus changes a threshold value for vacuum pressure in accordance with the amount of warp in the wafer, the threshold value being used to judge the imperfect adsorption. If the adsorptive activity of the transport arm decreases due to a change in the threshold value, the wafer transport speed is reduced in order to prevent the wafer to be displaced during transport.
When substrates in a horizontal posture are supported from the underside by a batch hand without being adsorbed as in the substrate processing apparatus in Document 1 and if these substrates are warped, the substrates may rattle (e.g., may shake or be displaced in the direction of transport), and this makes it difficult to stably support and transport the substrates.